Make socks_scheme arguments case-insensitive

HISTORY.rst

@@ -1,3 +1,8 @@
+dev
+-------------------
+
+- Make ``socks_scheme`` arguments case-insensitive. (#82)
+
 0.17.0 (2025-05-31)
 -------------------
 

pypac/parser.py

@@ -130,6 +130,7 @@ def parse_pac_value(value, socks_scheme=None):
 
     :param str value: Any value returned by ``FindProxyForURL()``.
     :param str socks_scheme: Scheme to assume for SOCKS proxies. ``socks5`` by default.
+        Case-insensitive.
     :returns: Parsed output, with invalid elements ignored. Warnings are logged for invalid elements.
     :rtype: list[str]
     """
@@ -145,6 +146,9 @@ def parse_pac_value(value, socks_scheme=None):
     return config
 
 
+_PROXY_SCHEMES = {"HTTP", "HTTPS", "SOCKS4", "SOCKS5"}
+
+
 def proxy_url(value, socks_scheme=None):
     """
     Parse a single proxy config value from FindProxyForURL() into a more usable element.
@@ -154,6 +158,7 @@ def proxy_url(value, socks_scheme=None):
 
     :param str value: Value to parse, e.g.: ``DIRECT``, ``PROXY example.local:8080``, or ``SOCKS example.local:8080``.
     :param str socks_scheme: Scheme to assume for SOCKS proxies. ``socks5`` by default.
+        Case-insensitive.
     :returns: Parsed value, e.g.: ``DIRECT``, ``http://example.local:8080``, or ``socks5://example.local:8080``.
     :rtype: str
     :raises ValueError: If input value is invalid.
@@ -167,9 +172,12 @@ def proxy_url(value, socks_scheme=None):
         if keyword == "PROXY":
             keyword = "HTTP"
         elif keyword == "SOCKS":
-            keyword = socks_scheme or "SOCKS5"
+            socks_scheme = socks_scheme.upper() if socks_scheme else "SOCKS5"
+            if socks_scheme not in _PROXY_SCHEMES:
+                raise ValueError("socks_scheme '{}' is not one of {}".format(socks_scheme, ", ".join(_PROXY_SCHEMES)))
+            keyword = socks_scheme
 
-        if keyword in ("HTTP", "HTTPS", "SOCKS4", "SOCKS5"):
+        if keyword in _PROXY_SCHEMES:
             return "{0}://{1}".format(keyword.lower(), proxy)
 
     raise ValueError("Unrecognized proxy config value '{}'".format(value))

pypac/resolver.py

@@ -25,6 +25,7 @@ def __init__(self, pac, proxy_auth=None, socks_scheme="socks5"):
         :param requests.auth.HTTPProxyAuth proxy_auth: Username and password proxy authentication.
             If provided, then all proxy URLs returned will include these credentials.
         :param str socks_scheme: Scheme to assume for SOCKS proxies. `socks5` by default.
+            Case-insensitive.
         """
         self.pac = pac
         self._proxy_auth = proxy_auth

tests/test_parser.py

@@ -181,6 +181,11 @@ class TestFindProxyForURLOutputParsing(object):
     def test_parse_single_value(self, pac_value, expected_result):
         assert parse_pac_value(pac_value) == [expected_result]
         assert proxy_url(pac_value) == expected_result
+        if pac_value.startswith("SOCKS "):
+            # socks_scheme must be case-insensitive
+            assert proxy_url(pac_value, socks_scheme="Socks4") == "socks4://foo:8080"
+            with pytest.raises(ValueError):
+                assert proxy_url(pac_value, socks_scheme="bad")
 
     def test_multiple(self):
         assert parse_pac_value("PROXY foo:8080; DIRECT") == ["http://foo:8080", "DIRECT"]

tests/test_resolver.py

@@ -19,6 +19,7 @@ def _get_resolver(js_func_return_value, proxy_auth=None):
     [
         "DIRECT",
         "PROXY foo:8080",
+        "SOCKS foo:8080",
     ],
 )
 def test_single_pac_value(pac_value):